Heater unit



Jan. l0, 1956 P, D, KlLBURY 2,730,349

HEATER UNIT Filed Feb. 9, 1955 i E, g mlm l "FTM- k INVENTOR.

2922 2o Q5 27 lo United States Patent O The present invention relates generally to heaters for a liuid medium, and is more particularly concerned with self-contained heater units of the type which may be mounted in the space to be heated or in some remote location with ducts provided to transmit the air, and which distributes a heated uid medium, such as air, by high velocity discharge from a blower or fan. More specifically, the invention is concerned with heaters of the gas type, wherein the burner jets are positioned directly in the airllow.

Heaters of the above mentioned type are especially adapted for utilization in the heating of large spaces such as warehouses, stores, markets, homes, oices, sanitoriums, and the like. Y

It is one object of the herein described invention to provide an improved gas heater in which the air is economically and efciently heated by means of a gas burner, and which will meet the established regulation requirements as to combustion and flame disposition with respect to the jet ports of the burner.

Heretofore, heaters of this type have presented an operational problem in that the utilization of an associated blower or fan for distributing the heated air at high velocity yresults in air movement adjacent the burner jets of such velocity that the jet llame is lifted away from the jet port so that relatively poor and incomplete combustion tends to result. For this reason, rather strict regulations have been established with respect to'flame lift in gas type heaters.

In its broad concept, the present invention proposes to provide stabilizing means which will reduce and tend to eliminate flame lift.

Briefly, the present invention accomplishes the above by providing in the heater compartment, a partition or baffle above the burner, this baille having a ow passage at its center of restricted size so as to stablize the upward ow velocity of air adjacent the burner, and thus obviate its tendency to lift the ilame at .the burner jet.

The above construction has the further advantage that the air is more efliciently heated and mixed, since the air which is heated directly by the burner is injected by induced flow into other air carried through a flow channel above the baille.

Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.

Referring to the accompanying drawings, which are for illustrative purposes only:

Fig. l is a perspective view of a heater unit embodying the features of the present invention;

Fig. 2 is a section through the heater compartment, taken substantially on line 2-2 of Fig. l; and

Fig. 3 isa horizontal section, taken substantially on line 3-3 of Fig. 2.

Referring now generally to the drawings, Fig. l illustrates a heater unit according to the present invention. The assembled unit comprises briefly a base structure, as

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generally indicated by the numeral 10, which serves as a support for a blower 1l elevated above the base and having a driving connection with an electric motor 12.

The blower 11 has an outlet duct 13 extending from its periphery for directing a high velocity discharge of air from one side of the base structure. Inlet to the blower is through an axially connected duct, not shown, which is secured to the blower casing in conventional manner and connects the axial blower inlet through an elbow 14 with a heater assembly, as generally indicated by the numeral 15.

The heater assembly is supported on the base structure on the opposite side of the blower from the driving motor 12. This heater is of substantially cylindrical construction, and, as most clearly shown in Fig. 2, comprises a heating compartment 16 which is substantially bounded by a peripheral wall 17 of foraminate material.

The base structure is shown as including a pair of spaced side rails 18 and 19 which in this instance support a burner 20 at the lower end of the heating compartment 16. As shown in Fig. 3, this burner comprises a circular hollow body 21 having diametrically opposed mounting lugs 22 by means of which the burner is supported and secured by lug bolts 22 in a position spanning the space between the rails 18 and 19.

As clearly shown in Fig. 3 the burner 20 is constructed with a plurality of burner jets 23 which project from the upper surface of the body 21 and may be arranged in various configurations. In the present instance, the burner jets are shown as being grouped into a plurality of concentric circumferentially extending rows 24 which surround a central opening 25. Adjacent the outer margin of the body 21, the jets are arrangedin a plurality of circumferentially extending concentric rows 26 which are separated from the inner group by spaced arcuate openings 27 between which are radially extending rows of jets as indicated by the numeral 28.

The body 21 of the burner has its hollow interior connected with a supply duct 29 which projects through the foraminate wall 17 and is arranged at its outer end for connection to a gas supply line 30. Adjacent the connection of the supply line 30, the duct 29 is formed into a flared end portion 31 containing primary air inlet openings 32 having an adjustable gate or valve 33 for regulating the amount of primary air ow into the duct for mixing with the gas to form a combustible mixture. Secondary air to the burner is supplied through the openings 25 and 27.

As shown in Fig. 2, the top of the heating compartment 16 is formed by a conical wall member 34 which is deformed at its periphery to provide an edge ange 35 which is connected in any suitable manner, for example by welding, with the upper edge of the wall 17. The wall member 34 is provided at its apex with an outlet opening 36 which is in communication with the connection elbow 14.

With the construction thus far described, the operation of the blower 11 will draw in through the openings in the wall 17 air which is to be heated by the burner 20 and discharged by the blower into the ambient air for heating purposes in the form of a directed stream of heated air from the discharge duct 13.

While such an arrangement is in the main satisfactory, it possesses the drawback wherein the upward movement of the air over the burner as it is sucked into the blower causes the jet llames'to be lifted away from the jet port exit openings. Such disposition of the ame is objectionable in that incomplete combustion may fail to be accomplished, and objectionable gases may be formed which are disseminated into the heated areas. For this reason, rather rigid regulatory requirements have been effected covering the operation of this type of burner.

The foregoing diculties have in the present invention been overcome by the utilization of a simple, but yet effective means for stabilizing the airflow over the burner jets so that the tendency to lift the ame is entirely elimi nated and greater eciency obtained. This is accomplished by providing a second wall member 37 of conical construction, this wall member being also provided at its periphery with a ange 38 by which it is secured to the adjacent wall 17. Centrally the wall member 37 is provided at its apex with an opening 39 which it will be noted is of smaller area than the opening 36 of the top wall 34.

From the above, it will be apparent that the wall member 37 separates the heating chamber 16 vertically so as to provide two separate ow channels, namely a ow channel below the wall 37 wherein air is conducted above the burner 20 so as to be heated, and a flow channel for other air above the wall 37 which is not directly conducted for heating purposes over the burner.

With this arrangement, the air in both cases flows radially toward the vertical axis of the heating compartment, and due to the restricted opening 39, the air below the wall 37 will be controlled in its upward moving velocity component so that a stabilized condition will be established at the burner wherein the ames at the jets will not be lifted and more complete combustion will be secured. Movement of the air above the wall member 37 acts to induce a flow of air upwardly through the opening 39, this air having been heated, and results in the injection of heated air along the axis of the heating chamber or compartment 16 into the substantially nonheated air above the wall 17. The two airows are then commingled and mixed as they enter the elbow 14 through the opening 36 and are thence conducted into therblower 11 Where further mixing and projection into the area to be heated is accomplished. Not only does this arrangement solve the problem of llame lift, but it also results in a novel method of operation by which heating efficient is accomplished.

From the foregoing description, it is believed that it will be readily apparent that the heater unit of the present invention provides a unique arrangement by which the indicated objects will be accomplished.

Various modications may suggest themselves `to those skilled in the art without departing from the spirit of my invention, and, hence, I do not wish to be restricted to 4 the Vspecific form shown or uses mentioned, except to the extent indicated in the appended claim.

I claim:

A space heater, comprising: a foraminate upright cylindrical shell; a top wall member for said shell of generally conical form, and having an apex outlet opening; a similar generally conical wall vmember positioned within said shell below and substantially in parallel relationship with said top wall with its base periphery engaging said shell substantially midway between the top and bottom of said shell, said second wall having an apex opening axially aligned with vthe opening of said top wall, but of relatively smaller area, said top wall and said second wall cooperating to deline a centrally located, vertically extending, unobstructed ow channel in said shell for up ward movement of air from the portion of said shell beneath the second wall, and an inwardly and upwardly inclined air passage between said walls for flow of air from the associated shell periphery into mixed relation with the air in said ow channel; a gas burner within said shell below said second wall and adjacent the bottom of said shell; and a blower having an inlet connected to the apex outlet of said top Wall adapted to withdraw said mixed air and discharge it into the space to be heated, said blower acting to induce airow through the apex openings of said walls, and said second wall acting to restrict and stabilize upward flow of air at said burner in a manner to prevent flame lift therein.

References VCited in the le of this patent UNITED STATES PATENTS 666,113 Schwickart Jan. 15, 1901 669,087 Hott Mar. 5, 1901 734,346 Mink July 21, 1903 738,186 Halliwell Sept. 8, 1903 883,880 Hensley Apr. 7, 1908 1,519,673 Doble Dec. 16, 1924 1,585,410 Olofson May 18, 1926 2,066,524 Gehnrich Jan. 5, 1937 2,107,365 Bray Feb. 8, 1938 2,206,553 Nagel July 2, 1940 FOREIGN PATENTS 950,242 France Apr. 9, 1945 

